7-Zip

7-Zip is an open source file archiver with a high compression ratio. The program supports 7z, ZIP, RAR, CAB, GZIP, BZIP2, and TAR formats. Compression ratio in the new 7z format is 30-50 percent better than ratio in ZIP format. It also compresses to ZIP 2-10 percent better than PKZip and WinZip. It has an additional powerful command line version and FAR Manager support.